Ecu 1g no good

[93AWDDSM]

Hey guys, so my car was acting up slightly few days ago. I first noticed a slight symptom then nothing for two days. On the third day, second time driving for the day it started sounding like it was misfiring bad. Checked for spark, made sure compression was in check, fuel and all that. It was late and I was running out of options and was stuck. Luckily my brother had a 92 ecu sitting around.


Sorry for the rant, my question is, how can we tell if the car has an original ecu?

Thanks.

 

[steve]

Hey guys, so my car was acting up slightly few days ago. I first noticed a slight symptom then nothing for two days. On the third day, second time driving for the day it started sounding like it was misfiring bad. Checked for spark, made sure compression was in check, fuel and all that. It was late and I was running out of options and was stuck. Luckily my brother had a 92 ecu sitting around.


Sorry for the rant, my question is, how can we tell if the car has an original ecu?

Thanks.

Clearly, the one in the picture with RTV covering the power supply capacitors isn't original.
All you can tell is if the ECU is correct for the car, not if it was the one it originally came from the factory with. Drowning the ECU with RTV is one of the shady repairs that cause more problems that it fixes. Usually after you dig all of they out you find that the capacitor leakage was never properly cleaned and has continued to eat away at the metals in the solder and traces.

Here's a list of what ECU part numbers go with which model car. http://simon.chi.il.us/ECU/ECUID.html

The last 4 digits of the E2T part number are printed on the white edge connector, which is one way to tell if the board is in the correct case.

 

[93AWDDSM]

First time with ecu issues. Does the ecu look like it can be repaired correctly if taken to - shop?

 

[steve]

I'm not sure that anyone will touch that ECU because of the time required to pick away the RTV to reach the circuit board to do any repairs.

BTW, That is a 91/92 FWD non-EPROM ECU. Note the 6574 on the connector which means it's from a E2T6574 MD166260 ECU.

 

[93AWDDSM]

Ya, I need to update my profile. I have a '92 TSi (fwd) M/T now.

So, toss this ecu and find another one, probably a good idea to send it in to verify and check over everything.

The ecu I'm using temporarily is from a awd '92 TSi, thanks to my brother. It runs just as well, if not better. I assume no harm done by doing this? His car is stock that I got the ecu from just as mine is.

 

[92AWDHX40]

I see them all the time for sale.

 

[93AWDDSM]

So a day an half after driving with the swapped ECU, everything was great - idle seemed normal besides that damn tick tick tick from lifters. Then yesterday I started my car and it had the same type of misfire issue. It stumbled when giving it gas and would not want to build boost at all - weird part, it sounded like a subie idling . Could a old knock sensor be picking up the ticks from the lifters and reporting it back to the ecu for limp mode?

- whats sensors should I all check for stuttering at idle/ power loss,misfire upon acceleration

 

[92AWDHX40]

Yes it could pick up that sounds.

 

[96dsmftw]

If the misfire is happening all the time an easy thing to check would be the resistance of the injectors. I had a injector that would run well cold to warm but if I tried to start the car warm it wouldn't work. The resistance was no good when it was warm but after it cooled down the resistance came into spec. Also, maybe boost leak for not building boost?

 

[93AWDDSM]

I think I found it. When I pulled the injector plug off while the car was running on cylinder 4 the car stayed running but when I pulled it from cylinder 1 the car wanted to die almost immediately. Does this mean that injector is dead? I'm assuming it's stock with 180k .


I took the multi meter and tested the good injector that changed idle when I pulled the connector and that was around 4 set at 2k ohm
The other injector which had no change in idle when the connector was removed wouldn't give me a reading on the multi meter and this was after I had just done around the block, a few good pulls because the intermittent problem went away then shortly returning leading me to belove one of the injectors is done.

Things I have tested:
•injector resistor box checked out
•New ecu that's not burnt or leaking
•compression test
•getting spark

UPDATE: as of 8:30AM 7/9 - The car ran fine this morning cold and into warmed up, didn't attempt to turn it off and see but when I arrived at work, which was about 15 minute drive from my place I tested the injector again and it showed some resistance same as cylinder 1. Could this possibly be a wiring problem now that's intermittent?